I have tried using Google Reader, FeedDemon and different Chrome extensions to follow Stack Overflow's tag feeds (e.g. newest question RSS feeds for a given tag), but nothing seems to give me alerts quickly enough. Even if I set the refresh time to as little as one minute, there is considerable delay. Any suggestions/recommendations for a faster tool or way of getting updates?

If you want to monitor it that quickly/actively, keep it open in a browser window which is set to refresh the page every ten seconds.
I think Opera allows that, and there'll be a Firefox plugin for sure. Probably plugins for other browsers too.

Or, stop worrying about it. Whilst I'm very much in favour of better efficiency, I'm not really sure why checking for updates every minute is not fast enough? :S